This invention relates generally to a variable high/low vacuum/blower device, and more specifically, to a vacuum/blower device that can be adjusted from a positive air outflow (blowing) through zero to a negative air inflow (suction). The vacuum/blower device can also be varied from a high pressure, low air flow operation through zero to a low pressure, high air flow operation. All of aforementioned functions of the vacuum/blower device operate through a single inlet/outlet port, with suitable air exhaust/intake ports or openings to work in conjunction with the single inlet/outlet port.
The first vacuum cleaner patented by Brooks in 1901 was powered by a five horsepower piston engine. While there have been many functional improvements in vacuum cleaners for economy, efficiency and ease of operation, the basic concept of vacuum cleaners has changed very little.
Basically, in the art today, a vacuum cleaner is an electrically powered fan unit designed to create an air stream moving through a pick up nozzle connected to a flexible hose. As the fan rotates, air is discharged from the periphery of the fan by centrifugal force, causing a partial vacuum at the center of the fan into which air rushes through the nozzle and hose. Where air is to be discharged in a blowing operation, the discharged air is forced out of the device, typically through a separate exhaust port. In the conventional type of vacuum cleaner where the device is used as both a vacuum and blower, the hose must be disconnected from the inlet port and connected to an outlet or exhaust port, in order to convert the device from a vacuum to a blower.
As distinct from conventional vacuum cleaner designs, the present invention is both a blower and vacuum device, while only using a single inlet/outlet port. At the same time, the vacuum cleaner of the present invention can be connected from a high pressure/low air flow operation to a low pressure, high air flow operation.
In the discussion that follows, the following background information will be of assistance in understanding the principles of the present invention. High or low pressure can be measured in inches water gauge (an instrument for measuring the amount of pressure; one inch wg=0.036 psi) or millimeters water gauge. Volume of air is measured in cubic feet or cubic meters of air displaced per minute, for example, cubic feet per minute or CFM. Thus, in the following discussion, the reference to high or low inches in terms of pressure is to be understood as referring to high or low pressure. Similarly, the reference to high or low cubic feet per minute (CFM) in terms of air displaced is also to be understood as meaning high or low air flow.